CAIE A Level Chemistry 9701 · Nitrogen and sulfur
Ammonia is a weak base. (a) State what is meant by the term base in the Brønsted–Lowry theory. (b) Compare the basicity of ammonia with that of a solution of sodium hydroxide, and explain why ammonia is described as a weak base. (c) Describe and explain how ammonia can be displaced from an ammonium salt, such as ammonium chloride, by reaction with sodium hydroxide.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Compare means: Give similarities or differences between two things, and say which side each point belongs to. Write each point as a pair, for example: A is X, whereas B is Y. Two separate descriptions rarely earn the marks.
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